Punching die set



Oct. 10, 1967 E. D. BENNETT PUNCHINC DIE SET 5 Sheets-Sheet 2 Filed Nov. 2, 1964 INVENTOR. EDW/IfiD D. BENNETT E. D. BENNETT PUNCHINC DIE SET Oct. 10), 1967 Filed Nov 3 Sheets-Sheet 5 F'lG 3 INVENTOR. EDWARD D. BENNETT BY w? United States Patent 3,345,896 PUNCHING DIE SET Edward D. Bennett, Union County, N.l., assignor to Minnie Punch & Die Company, 1110., Union County, NJ.

Filed Nov. 2, 1964, Ser. No. 408,003

9 Claims. (Cl. 83128) This invention relates generally to punching die sets and more particularly to a punching die set utilizing flat magnesium punch and die plates with unique guide pin, shedder and stripper members. a

The conventional die set is constructed of steel, is connected to the ram of a punch press and is relatively heavy to work with, difficult to set upand expensive to manufacture. Their accuracy depends to some extent upon the alignment of the ram to which the die is attached. It is to the manufacture of an economical yet accurate punching die set that this invention is directed.

It is therefore a broad object of the invention to provide an improved punching die set.

It is a further object of the invention to provide a light weight punching die set with improved guide pin, shedder and stripper members.

It is a feature of the invention that the punching die set has easily removable guide pins for facilitating sharpening of the punches and for interchangeable use.

It is a further feature of the invention that a removable shedder is provided for ejecting the punched part from the blanking die. 7

Another feature of the invention is the use of a removable support stripper which acts to support thedie set and acts to strip the stock from the blanking punch after the punching operation. 7

Another feature of the invention is the construction and use of a removable shedder actuator which may be readily locked in position against longitudinal and rotative movement.

Other objects, features and advantages will hereinafter appear.

In the drawings: 7

FIG. 1 is a partial cutaway View of the die set of the present invention shown in the open position.

FIG. 2 is a partial cutaway view of the die setof the present invention shown in the closed position.

FIG. 3 is a section taken on the line BB of FIG. 1.

FIG. 4 is a section taken on the line CC of FIG. 1.

FIG. 5 is a detail showing the shedder actuator with the die set in the open position.

FIG. 6 is a detail of the shedder actuator with the die set in the closed or punching position.

FIG. 7 is a detail of the support stripper with the die set in the open position.

FIG. 8 is a detail of the support stripper with the die set in the closed or punching position, taken along line A-A of FIG. 2.

FIG. 9 is a top view of theshedder actuator as shown in FIG. 6.

The inventionis directed to a parallel plate punching die set in which a ram or other drive acts to compress bushings 12 in the punch plate and guide bushings 14 in the die plate, the retaining rings 16 preventing the escape I of the guide pins from the die plate bushings. It is thus 3,345,895 Patented Oct. 10, 1967 seen that the guide pins are secured in bushings 12 and ride in bushings 14. Springs 18 encircle each of the guide I pins and urge the two plates apart while the retaining other die sets.

The die set rests on the base 22 on removable mounting blocks 24, removable support blocks 26, and removable support strippers 28. A ram plate 30, activated by a press or other drive means moves to engage the top surface of the punch plate 4 to drive the punch plate down to, perform the punching operation. Another important feature of the invention is that by this arrangement, any'misalignment of the ram is not transmitted to the die set since the guide pins determine the die set alignment.

Referring now to FIGS. 1, 2, and 5, attached to the punch plate 4 is a blanking die 32 having a shedder plate 34 and a floating shedder pin 36. A shedder actuator 38 is mounted in the punch plate proximate the shedder pin 36. FIGS. 1 and 5 illustrate the relative positions of the shedder actuator 38 and shedder pin 36 when the die set isopen. The shedder retaining stud 49 is affixed to plate 34 by bolt 47. Stud 49 moves in cylinder 51 and acts to limit movement of plate 34.

Referring to FIGS. 5 and 9 the shedder actuator 38 comprises a circular housing 40 having a shoulder 42 formed therein. Circular washer or disc springs 29 fill the cavity 46 of the housing 40 and press against the punches in their proper position.

It is thus seen that the removable shedder actuator is secured or removed by the locking means 42, 50, and 52. Being removable the actuator is interchangeable with other similar die sets.

FIGS. 2 and 6 illustrate the shedder actuator during the punching operation, when the ram plate 30 moves against. the punch plate. The punched piece part 54 presses against the shedder plate 34 and moves the shedder pin 36 against the movable end 48 of shedder actuator 38 so as to compress the springs 29 in cavity 46, as shown in FIGS. 2 and 6. Upon release of pressure by plate 30 the springs 44 act to move the end 48 against pin 36 to drive. the'shedder plate against the punched piece part to forcibly eject the piece part.

The die plate 6 is supported on and secured to the base 22 by means of the removable mounting blocks 24 shown in FIGS. 1, 2, and 3. Removable support block 26 also acts to help support the die plate 6.

The blanking punch 56 is secured to the die plate 6 and acts as a stationary punch to the moving blanking die in the punching operation. Removable support strippers 28 act to support the die set and eject the stock material from the blanking punch after the punching operation. FIG. 7 shows a detail of the support stripper y when the die set is in the open position. Circular washer springs 29 are stacked in the cavity 31 proximate the support stripper actuating pin 35. Stripper 28 is placed on pin 35 by hand pressure. The O-ring or grommet 7 on the end of the pin 35 compresses and moves through the pad 33 so as to join the pin 35 and stripper 28. Downward movement of the pin 35 compresses washers 29 so that upon release of punch pressure washers 29 act to move the pin 35 upward to strip the piece part from the blanking punch 56. The grommet or resilient member 7 retains the housing against the pull of gravity yet allows easy removal.

FIGS. 2 and 8 illustrate the support stripper in the compressed position, as when punching and shows the stripper plate 37 as secured by head 39 and bolt 41. A liquid adhesive on the threads of bolt 41 prevent creeping. The retaining ring 43 acts to prevent the support stripper from falling from the pin 35. An important feature of the invention is that the head 39 protrudes above plate 37 a distance equal to at least twice the thickness of the piece part material. Normal operation is to shed the piece part and then strip the material skeleton. improper distance of the head above the plate 37 will cause improper shedding and stripping in that the stripper will drive the skeleton back around the part.

The protrusion need not be connected to the stripper pin nor is it necessary that the protrusion be on the bottom. The above description illustrates one embodiment W1 ich has proven successful.

It should be noted that the preferred operation is to shed the piece part prior to stripping the stock. This is accomplished by having the stripper plate move down, during the punching operation, a distance more than twice the thickness of the stock from which the piece parts are punched. Therefore, upon release of pressure by the ram, the shedder will eject the piece part prior to the stripper plate moving up far enough to strip the stock from the die set.

As may be seen from the drawings and the above description the invention describes a light-weight punching die set having removable guide pins, shedder and stripper members. Magnesium has proven to be particularly suitable because of its lower cost, flatness accuracy, ease of machining and light-weight. Other materials may be used in some instances without departing from the spirit of the invention.

The removable feature of the guide pins allows the pins to be used interchangeably and therefore separate sets of guide pins do not have to be maintained for use with each die set. The ease with which the removable guide pins facilitate disassembly of the die set allows the operator to easily separate the punch plate from the die plate to sharpen the punches or make other necessary repairs or adjustments to the die set.

The removable shedder and support stripper members provide means for forcefully ejecting the punched piece part and releasing the stock from which the piece is punched.

By being removable the shedder actuator and support stripper may be used interchangeably on other die sets of the same general type thereby eliminating the need for having a complete set of actuators for each die set.

The internal actuator constructions provide forceful positive action with a minimum of parts.

It is thus seen that the objects set forth are accomplished by the invention as shown and described herein and it should be realized that modifications and variations of the above described invention are contemplated by the following claims in which.

I claim:

1. A punching die set for use on a base and to be actuated by a ram comprising a substantially flat magnesium punch plate, a substantially fiat magnesium die plate, mounting means for mounting the punch plate and die plate in parallel for movement toward and away from each other whereby movement of the ram contacts the punch plate and compresses the die set between the ram and the base.

2. A punching die set for use on a base and to be urn punch plate, a substantially flat magnesium die plate, mounting means for mounting the punch plate and die plate in parallel for movement toward and away from each other the mounting means including interchangeable guide pins having annular slots around their periphery, preloaded springs mounted to tend to separate the punch and die plates and first guide pin retaining rings placed in the guide pin annular slots so as to secure the guide pins to the punch plate and second guide pin retaining rings placed in the guide pin annular slots so as to allow a portion of the'guide pin to move through the die plate during the punching operation but to limit the return travel of the punch plate under the urging of the preloaded springs, to the normal open position of the die set whereby the guide pins maintain alignment between the punch and die plates when the die set is compressed between the ram and the base.

3. A punching die set for operation between a ram and a base to punch piece parts from stock comprising a substantially flat magnesium punch plate, a substantially flat magnesium die plate, mounting means for mounting the punch plate and die plate in parallel for movement toward and away from each other, blanking die means including a shedder plate connected to the punch plate to move therewith and to receive a piece punched from a strip of stock, blanking punch means including a stripper plate connected to the die plate, removable shedder actuator means including a shedder actuator and shedder actuator pin mounted in the punch plate and blanking die for ejecting a piece after punching from a strip of stock, and removable support stripper means mounted proximate the die plate for stripping the stock web from the blanking punch after the punching operation.

4. Apparatus according to claim 3 in which the mounting means includes removable guide pins slip fit mounted in guide bushings which are press fit in the magnesium punch and die plates, the guide pins having annular slots around their periphery, preloaded springs mounted to tend to separate the punch and die plates and first guide pin retaining rings placed in the guide pin annular slots so as to secure the guide pins to the punch plate so as to move with the punch plate and second guide pin retaining rings placed in the guide pin annular slots so as to allow a portion of the guide pin to move through the die plate bushing the punching operation but to limit the return travel-of the punch plate, under the urging of the preloadedsprings, to the normal open position of the die set, whereby alignment between the punch and die plates is maintained by the guide pins and not by the ram.

5. Apparatus according to claim 3 in which the removable shedder actuator means comprises a shedder actuator mounted in the punch plate, and having a spring loaded pad, a shedder actuator pin mounted in the blanking die proximate the shedder actuator so that during the punching stroke of the die set the shedder plate of the blanking die forces the shedder actuator pin against the spring loaded pad of the shedder actuator so that upon release of pressure .from the punch plate after the punching operation, the spring loaded pad forces the shedder actuator pin against the blanking die shedder plate to forcefully eject the punched part from the blanking die.

6. Apparatus according to claim 3 in which the removable support stripper means comprises a housing having a spring loaded compressible pad and support stripper pin placed so that the housing supports the die plate with the support stripper pin extending through the die plate and connected to the blanking punch stripper plate so that during the punch operation the support stripper pin is depressed by the stock from whichthe piece is punched and upon release of the punching pressure the spring loaded pad acts through the pin to strip the stock from the blanking punch.

7. In a punching die set for punching piece parts from stock a removable stripper actuator for use with stripper actuating means having a longitudinally movable pin associated therewith comprising a housing having washer springs therein and having an aperture formed in a portion of the housing whereby the housing may be placed upon the die set pin to act to strip stock from the die set or removed .from the pin to be used on another die set of similar construction.

8. Apparatus according to claim 7 wherein the housing is attached to the die set pin by means of a resilient member capable of holding the housing against the force of gravity but easily removable by hand.

9 In a punching die set having substantially parallel plates including apertures for guide pins, guide pin means for aligning the plates of the die set comprising a plurality of removable guide pins having a plurality of 15 annular slots formed therein, guide pin retaining rings placed in annular slots in the guide pins on each side of one of the plates to secure each guide pin to one plate, and still other retaining rings placed on the outer side of a second plate to limit the movement of the second plate from the first plate whereby the removable guide pins act to align the plates of the die set and yet are easily removable.

References Cited UNITED STATES PATENTS 1,683,501 9/1928 Tobler 83-143 2,208,858 7/1940 Schneider 83143 2,379,003 6/1945 Hedberg 83--143 3,064,511 11/ 1962 Allander 83143 X 3,211,034 10/1965 Andris 83-128 X FOREIGN PATENTS 789,408 1/ 1958 Great Britain.

WILLIAM W. DYER, 111., Primary Examiner.

WILLIAM S. LAWSON, JAMES M. MEISTER,

Examiners. 

2. A PUNCHING DIE SET FOR USE ON A BASE AND TO BE ACTUATED BY A RAM COMPRISING A SUBSTANTIALLY FLAT MAGNESIUM PUNCH PLATE, A SUBSTANTIALLY FLAT MAGNESIUM DIE PLATE, MOUNTING MEANS FOR MOUNTING THE PUNCH PLATE AND DIE PLATE IN PARALLEL FOR MOVEMENT TOWARD AND AWAY FROM EACH OTHER THE MOUNTING MEANS INCLUDING INTERCHANGEABLE GUIDE PINS HAVING ANNULAR SLOTS AROUND THEIR PERIPHERY, PRELOADED SPRINGS MOUNTED TO TEND TO SEPRATE THE PUNCH AND DIE PLATES AND FIRST GUIDE PIN RETAINING RINGS PLACED IN THE GUIDE PIN ANNULAR SLOTS SO AS TO SECURE THE GUIDE PINS TO THE PUNCH PLATE AND SECOND GUIDE PIN RETAINING RINGS PLACED IN THE GUIDE PIN ANNULAR SLOTS SO AS TO ALLOW A PORTION OF THE GUIDE PIN TO MOVE THROUGH THE DIE PLATE DURING THE PUNCHING OPERATION BUT TO LIMIT THE RETURN TRAVEL OF THE PUNCH PLATE UNDER THE URGING OF THE PRELOADED SPRINGS, TO THE NORMAL OPEN POSITION OF THE DIE SET WHEREBY THE GUIDE PINS MAINTAIN ALIGNMENT BETWEEN THE PUNCH AND DIE PLATE WHEN THE DIE SET IS COMPRESSED BETWEEN THE RAM AND THE BASE. 